Grooving center block journal?


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By Philo - 14 Years Ago
I've been researching rocker arm related info on the site and have a question about connecting the 3 holes in the block cam journal with a groove to increase oil flow to the rockers. I imagine this is done with a die grinder and narrow grinding wheel? If this is true, then what width and how deep??

I understand that restrictor plugs would then be needed in the oil passages in the heads or rocker stands to prevent flooding of the valve chamber even with unrestricted return tubes.

What is the advantage gained by this modification?



HAPPY NEW YEAR!
By Ted - 14 Years Ago

The groove will be adequate being between 0.040 & 0.060” wide and a mininum of 0.030” deep.  These are minimum values so being larger than these values is not a detriment.  Be careful when cutting the groove that you don’t nick the journal surface leading to the outside of the journal hole to the point that oil can free flow when under pressure to the blocks interior once the cam bearing is installed.  Here’s a couple of pics of the added groove when looking at it with a mirror.

   

And here’s a pair of pics of the tool that was made to facilitate putting the groove into the center cam journal.

   

The indepth article covering this in more detail is in the May-Jun 2009 (#92) issue of Y-Block Magazine.

By grovedawg - 14 Years Ago
I've been looking for this for TWO WEEKS! Thanks for posting the info!
By Rono - 14 Years Ago
guys;

Here's another option; Schumann's Sales and Service is selling a cam bearing set where the center cam bearing is grooved on the O.D. So it won't matter if the bearing is mis-aligned on installation or if the bearing spins, you will still get oil to the rockers. Seems to methis would save you alot of work.

Rono. 

By PF Arcand - 14 Years Ago
What I don't recall being mentioned in any the discussions of top oiling is this. According to Eickman's Y-Block book, three different styles of cam bearings were used in the oil supply position. Which begs the question, which style is normally being sold now? Another factor is that according to John Mummert, many replacement cam cores sold in the recent past, had the oiling grooves turned to shallow. Further, Ted has mentioned that some inferior Cam bearings are on the market. Which ones? How can a rebuilder know which parts he's working with?. This is an area of a Y-Block engine rebuild, that is really cloudy & needs positive clarification. I'm sure a further in depth discussion here and or an article in YBM is warranted...
By chiggerfarmer - 14 Years Ago
I second the idea about more info on cam bearings. I sure would like to know of the brands/kinds, etc that seem to be inferior.
By 314 - 14 Years Ago
the bearings sold today are for the grooved cam but you can still get them for the crossdrilled.i only bought a few sets for the y and got no less than 2 bad sets.the first set came in a federal mogul box over 20 years ago.you could almost push them in by hand.the second set i got from j c witney and the holes didnt line up.i wonder how many got a set of those.that was about 10 years ago.
By Ted - 14 Years Ago

The grooved camshaft will effectively supply oil to the topend regardless of the cam bearing style being used.  It’s the cross drilled camshafts that do get a bit picky on the bearing style.  If not doing the aforementioned grooving in the center cam bearing hole or on the backside of the bearing, then the three oil holes in the cam bearing must still be properly aligned with those in the center cam hole in the block regardless of which style cam bearing is being used.  Grooving the center cam hole in the block or the grooving the outside of the cam bearing itself takes the cam bearing style out of the equation altogether.  The hole in the bearing allowing oil to feed to the camshaft itself still needs to be aligned with the same hole that feeds down to the mains though.

 

The latest Sealed Power cam bearings are of the soft babbitt design.  Believe the number is 1160M without looking this up.  These particular bearings were ‘hard’ and when Sealed Power changed the bearing design so that one part number would fit both grooved and cross-drilled cams, the bearings went to using a softer material.  The part number did not change when the bearing design and material changed so that really compounds the problem on that particular bearing.  For my own builds, I prefer the Durabond cam bearings which is a division of Melling.

 

Here are some Durabond cam bearing numbers for the Y-Blocks.

For grooved camshaft – F9A

For crossdrilled camshaft – F9B
By cos - 6 Years Ago
Thanks Ted for info. I saw a picture of a build you were doing with a drill motor, do you use a abrasive wheel also? Thanks for links Bill Oregon
By Brent - 5 Years Ago

Ted's earlier post seems to indicate that a grooved cam solves the top end oiling issues. I intend to use one of John's cams:
http://www.ford-y-block.com/valvetrain.htm  and forego the center journal groove.

I have edited my earlier posted question after reading and then rereading these posts.

Thanks to all of you for sharing your experience and knowledge... There is no doubt that my engine has benefited!
THANKS!!!
By darrell - 5 Years Ago
you can cut the groove deeper in any cam without buying a new one.not many people cut the groove in the block unless your using heavy spring pressure.
By NoShortcuts - 5 Years Ago
Brent.  Darrell's comment is a GooD one regarding valve spring pressures.  IMO valve spring pressure NECESSARY depends upon cam lobe ramps, valve lift, AND the operating RPM you're realistically going to use with your engine use application.  I don't like to use more spring pressure than necessary! 

I consider the use of Verne Schumann's Dura-Bond F-9A y-block camshaft bearings w/ the 360 degree perimeter groove in the O.D. of the center cam bearing as oiling assurance for y-block rocker arm assemblies.  In using Verne's bearings, as Ted indicated, the hole in the bearing allowing oil to feed to the camshaft itself must be aligned with the hole that feeds up from the crank main bearing.

As a hobbyist, I try to do things in a manner that doubly assures that I won't have to do them again because of any problem. 

I think you can obtain Verne's modified cam bearings from John Mummert.  IF not, Verne's address is Schumann's Sales & Service Inc.  227 W. Mayne St.  Box 128  Blue Grass, IA  52726.  There is no web address or e-mail address to reach Verne.  I recommend calling him @ 563-381-2416.  Check your time zone difference in calling.

John or Geoff Mummert or Ted Eaton can advice you as to what springs to use with the camshaft being used and the maximum RPM you're going to operate your valve train assembly.

I'd like to hear about the use of bee-hive springs for street applications to reduce valve spring cam lobe and cylinder head seat pressures, and cam bearing wear issues.

Food for thought.    Smile